Spark Plugs. Fits Big Twin 1948-1975.

Autolite® Copper spark plugs are engineered to deliver quick starts and the power your vehicle or applications needs to meet performance expectations.

*Sold Each

*Autolite Number: 4275

*The copper core center electrode aids in thermal control and improves resistance to fouling.

*Its specially engineered high nickel alloy center and ground electrode provides extended life.

*The high alumina multi-rib ceramic insulator provides thermal conductivity and superiorinsulation for increased strength.

*Designed with a nickel-plated shell that is corrosion resistant to provide increased durability for extended periods.